Regarding a rectification power supply circuit, there has been proposed “a rectification power supply circuit including: a rectifier which rectifies an alternating current voltage and outputs a direct current voltage; a reactor connected in series to an alternating current input side or a direct current output side of the rectifier; a capacitor to which the direct current voltage output from the rectifier or the direct current voltage output via the reactor is applied via a diode, the capacitor acquiring a smoothed direct current voltage; a switch element which establishes a short circuit at a direct current output side of the rectifier directly or via the reactor; a voltage control means which outputs a voltage control signal in accordance with a deviation value between a voltage reference and the direct current voltage smoothed by the capacitor; a current reference calculating means which calculates a product of a sinusoidal synchronization signal in synchronization with the alternating current voltage or a sinusoidal full-wave rectification synchronization signal and the voltage control signal, and outputs a current reference signal; and a comparison means which compares the current reference signal and an alternating current side current or a direct current side current of the rectifier and outputs a driving signal for ON/OFF control of the switch element, in which the direct current output voltage is controlled to a desired value while controlling an alternating current input current in a sinusoidal form” (Patent Document 1).
Regarding an alternating-current direct-current converter, as a technique for solving a problem that “in a configuration in which a full-wave rectifier circuit formed using a single-phase alternating current power supply and a diode, a reactor, a capacitor series circuit, a bidirectional switch and a load are connected together, the voltage of the capacitor connected in series becomes nonuniform during a half cycle when the power factor of an alternating current input current is improved by switching of a bidirectional switch,” it has been proposed that “in a configuration in which a reactor is connected between a single-phase alternating current power supply and one alternating current input of a full-wave rectifier circuit formed using a diode, a capacitor series circuit is connected between direct current outputs of the full-wave rectifier circuit, bidirectional switches 10 and 11 are connected between an internal connection point of the capacitor series circuit and each alternating current input of the full-wave rectifier circuit, and a load 14 is connected in parallel with the capacitor series circuit, voltages of a capacitor 12 and a capacitor 13 which are connected in series are detected and the bidirectional switches 10 and 11 are subject to ON/OFF control at a high frequency such that the detected voltages become uniform” (Patent Document 2).
As a technique for the purpose of “obtaining a direct current power supply unit capable of reducing harmonic components of an input current and optimumly improving a power factor,” it has been proposed that “when an alternating current voltage of an alternating current power supply passes through a zero point, the switching means is operated to close after a predetermined first delay time has elapsed from the time of passage and the switching means is operated to open after a predetermined second delay time has elapsed from the time of passage” (Patent Document 3).
As a technique for the purpose of “reducing a control process speed, improving a power factor, reducing a harmonic and reducing costs through the reduction of the number of switching events to the minimum that is necessary,” the following has been proposed “the inclusion of a rectifier circuit 2 which rectifies a voltage of an alternating current power supply 1; a smoothing capacitor 4 which smoothes an output voltage from the rectifier circuit 2; a switching means 6 disposed further toward the alternating current power supply 1 than the smoothing capacitor 4; a reactor 3 disposed further toward a power supply than the switching means 6; a load quantity detection means 10 which detects a load quantity of a load connected in parallel with the smoothing capacitor 4; and a control means 8 which controls opening and closing of the switching means at opening and closing time in accordance with the load quantity at least twice during a half cycle of the power supply in synchronization with the alternating current power supply 1” (Patent Document 4).
As a technique for the purpose of “enabling, in a converter circuit which converts an output voltage of an alternating current power supply 1, a voltage greater than an input voltage to be generated without using a reactor or a large capacitance capacitor,” it has been proposed that “in a converter circuit 100 which converts an output voltage of an alternating current power supply 1, a rectifier circuit 20 which rectifies the output voltage of the alternating current power supply 1; first and second capacitors 31, and 32 connected in series which smooth an output of the rectifier circuit 20; and a switching circuit 40 which switches connections between the capacitors 31 and 32 and the alternating current power supply such that the output voltage of the alternating current power supply 1 is alternately applied to the first and second capacitors 31 and 32 repeatedly in a cycle shorter than that of the alternating current power supply, are included” (Patent Document 5).
As a technique for the purpose of “providing an electric power unit capable of satisfying a regulation on a power supply harmonic and providing both boost performance of an electric power unit and an input power factor at high levels,” there has been proposed providing of “an electric power unit including: a rectifier circuit; a capacitor circuit which is formed using a plurality of capacitors connected in series, and is connected between two output terminals of the rectifier circuit; a first switching means connected between one input terminal of a rectifier circuit and one connection point between the capacitors in the capacitor circuit; a second switching means connected between the other input terminal of the rectifier circuit and one connection point between the capacitors in the capacitor circuit; and a zero crossing detection means which detects a zero crossing point of an alternating current power supply, in which for each half cycle of the alternating current power supply, both the first and second switching means are turned ON for a predetermined time t1 after the zero crossing point of the alternating current power supply, then only the second switching means is turned OFF for a predetermined time t2 and, thereafter, the first and second switching means 8 are turned OFF” (Patent Document 6).
A technique to control a harmonic current through an operation of two switching elements has also been proposed (Nonpatent Document 1).
[Patent Document 1] Japanese Examined Patent Application Publication No. 7-89743 (Abstract)
[Patent Document 2] Japanese Unexamined Patent Application Publication No. 2008-22625 (Abstract)
[Patent Document 3] Japanese Unexamined Patent Application Publication No. 7-7946 (Abstract)
[Patent Document 4] Japanese Unexamined Patent Application Publication No. 2000-125545 (Abstract)
[Patent Document 5] Japanese Unexamined Patent Application Publication No. 2005-110491 (Abstract)
[Patent Document 8] Japanese Unexamined Patent Application Publication No, 2008-99512 (Abstract)
[Nonpatent Document 1] Shinichi Hoshi, Oguchi Kuniomi, “A Switching Pattern Decision Scheme for Single-phase Multi-level Rectifiers” (2005 Annual Conference of I.E.E. of Japan, Industry Applications Society) No. 1-61